class Stack:
	def __init__(self):
		self.items = []
	def is_empty(self):
		return self.items == 
	def push(self, item):
		self.items.append(item)
	def pop(self):
		return self.items.pop()
	def peek(self):
		return self.items[len(self.items)-1]
	def size(self):
		return len(self.items)
s = Stack()
print(s.is_empty())
s.push(4)


